Scanning Electron Micrograph (SEM) depicting large numbers of Staphylococcus aureus bacteria, which were found on the luminal surface of an indwelling catheter. Of importance is the sticky-looking substance woven between the round cocci bacteria, which was composed of polysaccharides, and is known as biofilm. This biofilm has been found to protect the bacteria that secrete the substance from attacks by antimicrobial agents such as antibiotics. Staphylococcus aureus, also known as "golden staph" and Oro staphira, is a facultative anaerobic Gram-positive coccal bacterium. Staph bacteria are one of the most common causes of skin infections in the United States. Most of these skin infections are minor such as pimples and boils, and can be treated without antibiotics, which are also known as antimicrobials or antibacterials. However, staph bacteria also can cause serious infections such as surgical wound infections, bloodstream infections, and pneumonia. Magnification: 2363x.